imo these are the pros and cons of each.. just depends which ones matter more to you
s9/9 dual pros:
1 base .. 1 cat can reach any towers
dual from start.. faster peons
11 is awesome expo
8 is not a horrible expo imo
s9/9 cons:
-need to expand earlier than a 4/5 counter dual
-some say due to a straight dual, you're "playing in the dark" not knowing what the other person is doing. I don't entirely agree with that. in most cases you can tell a lot about what they're doing just by how they handle their grunts and what lvl the grunts are
.. i just smoked some weed and cant finish sorry